12 volt accessories?

[cinergi]

Thank you for sharing Scott. I have a Magellan GPS plugged in the cig lighter socket. When I turn off the car it asks if i want to use the internal battery so i assumed the 12V shuts off. One night I let the GPS use it's own battery and figured it would be dead in the morning but it was on. I thought that was impressive but since the car was plugged in I guess the 12V plug was live.

So what about the "use internal battery?" screen on the GPS when the car is shut off? Well sometimes i see it come on when driving down the road. The "use battery?" screen stay on for about 3 to 5 seconds. I thought at first it was a loose 12V connection where it plugs in but am confident in that connection now and that the car is somehow-for some reason shutting the power off to the 12V momentarily. It still could be a loose connection somewhere in the car (1.5 cars do not have the 12V battery) but I wonder if it's a circuitry thing. That same sort of shut off may happen when the car is turned off.
?

Anyone else notice a similar while-driving loss of 12V power?

Not quite what you're describing, but I have noticed that when my ABS activates, the 12V system drops enough voltage that my radar detector shuts off (low-voltage battery shutoff). I wonder if yours is teetering on thinking low-voltage condition.

[vfx]

Not quite what you're describing, but I have noticed that when my ABS activates, the 12V system drops enough voltage that my radar detector shuts off (low-voltage battery shutoff). I wonder if yours is teetering on thinking low-voltage condition.

Sure, that could be it. It seems like it happens when I'm just driving but I'll look for an ABS coincidence.

[cinergi]

This just happened to me when regen re-enabled. As soon as the light on the dash disappeared, my radar detector reset. There must be certain system events that cause the 12V system to dip or something ...

[markwj]

Yes. The 12V cig lighter appears to run off Vaps. This causes a somewhat misleading user experience. To the user, it seems that the 12V cig lighter is always on, but it is not it. It only stays on for the first ~5min after the car is turned off.

Thanks for this. It was confusing the hell out of me.

[markwj]

Hmm... Looks like this:
http://www.sepbatteries.com/pt7b-4-p...c-battery.aspx

Interesting. We used to use large numbers of an almost identical battery for powering underwater 50watt lights while cave diving. We saw drops of about 30% burn-time after the first 100 or so discharges. Under heavy use, we'd change to new ones once a year or two. Admittedly, the environment was harsh (salt water, high humidity). Good news is that they are relatively cheap, and very simple to charge.

Nowadays, this has been replaced with Lithium Ion batteries and HID/LED lamps. Same burn time, an a much nicer light, for 1/4 the weight.

[Doug_G]

12V battery looks like this:

[zack]

I'm extremely curious about continuous 12VDC power for a sophisticated alarm system so I wrote to ask about it... here's the response I got today:

Zachary,
I have received a response from our engineering staff and it is highly likely that the alarm system will drain the Backup power source and you will get BPS problem faults, damage the Vehicle Management System or the Switch Pack. Hence this sort of a system is not recommended beyond the on board alarm system.
With this in mind they have requested the power consumption data of the alarm system for review.
If you have this information and can forward it to me I can pass it to our engineering staff.
Lawrence

[cinergi]

Anyone run a 12V air compressor from the accessory outlet? In my recent move, I had to get rid of my big 120V compressor and am looking for a portable alternative. I'd rather not use a rechargeable one (weight and stamina reasons), but all the ones I'm seeing say they consume ~14 amps and the outlet is rated for 10.

[ggr]

Anyone run a 12V air compressor from the accessory outlet? In my recent move, I had to get rid of my big 120V compressor and am looking for a portable alternative. I'd rather not use a rechargeable one (weight and stamina reasons), but all the ones I'm seeing say they consume ~14 amps and the outlet is rated for 10.

I have a little one that came with my Mercedes, and have run it from the Tesla without trouble. I don't know what current it draws though.

[smorgasbord]

12V battery ....

Finding out my high-tech Roadster needs a motorcycle battery is a major bummer.